With the increasing use of genetic engineering techniques, commercial scale production of many proteinaceous materials has become possible. Once a protein becomes available in large quantity, researchers can then more easily study it and its function, and they can use it for other purposes that require relatively large quantities of the protein. Of course, even where commercial scale production techniques are available, there is always a desire to lower the cost and time involved in the production of such proteins.
One technique that the art has tried to make production more efficient is to locate efficient DNA promoter sequences that occur in nature, and then use them in order to improve the efficiency of "transcription" of DNA to RNA. Another approach has been to develop means to culture eukaryotic host cells, so as to provide suitable hosts to permit "translation" (RNA to protein) of certain proteins that need host proteins to be expressed. This approach is costly, involves separation problems, and is not universally applicable.
Yet another approach is to create "cell free" extracts (e.g. derived from rabbit reticulocytes) so as to provide an in vitro media for translation of RNA to proteinaceous material. See e.g. D. Shih et al., 30 J. Virol. 472-480 (1979); S. Gupta et al., 144 Virol. 523-528 (1985). The disclosure of these articles (and all of the other articles recited herein) are incorporated by reference as if fully set forth below. Unfortunately, in vitro translation of certain RNA (e.g. polio virus and rhinovirus) has been inefficient in such media.
In the past, researchers have conducted general research into various viruses known as cardioviruses. These picornavirus RNA viruses do not go through a DNA stage in their life cycle. Encephalomyocarditis virus ("EMC"), Mengovirus, Mous-Elberfeld virus, MM virus, and Columbia SK virus are examples of cardioviruses. It has been learned that these viruses have relatively efficient translation of their coding RNA in cell free systems. It has also been learned that there are various techniques for culturing and producing the natural cardioviruses. Some work has also been done on sequencing these viruses. See generally H. Pelham, 85 Eur. J. Biochem. 457-463 (1978); A. Palmenberg et al., 32 J. Virol. 770-778 (1979); A. Palmenberg, 41 J. Virol. 244-249 (1982); R. Rueckert et al., 78 Meth. Enzym. 315-325 (1981); C. Shih et al., 40 J. Virol. 942-945 (1981); A. Palmenberg, 44 J. Virol. 900-906 (1982); A. Palmenberg et al., 12 Nucl. Acid. Res. 2969-2985 (1984); R. Rueckert et al., 50 J. Virol. 957-959 (1984); K. Chumakov et al., 246 Dokl Biochem 209-212 (1979).